Method for confining and removing spray drift

ABSTRACT

A method is described for spraying toxic chemicals onto agricultural plants that produces only a small amount of contained drift and then removes this drift from the air polluted. 
     The environment is not badly damaged, less toxic chemical is used, the probability that a user will injure anyone with toxic spray drift is reduced and spraying work is made more tolerable.

CROSS REFERENCE TO RELATED APPLICATION

Disclosure Document #210567 received by Commissioner of Patents andTrademarks on Sept. 19, 1988.

BACKGROUND FIELD

This invention relates to spraying toxic pesticides, fungicides orbactericides onto agricultural plants. And, specifically, it relates tospray drift, the misdirected fraction of the spray that does not fall onthe intended plants.

BACKGROUND OF PRIOR ART

Commerical, agricultural growers spray toxic chemicals on a regularbasis, throughout the growing season, to keep from losing their plantsand fruit to insects, mites and disease pathogens.

This spray is, generally, in the 500 to 2 micron particles range. Whilethe finer particles result in better leaf coverage, they also drifteasily. This fraction of the spray mist that is not applied, to theagricultural plants, is misdirected. It causes excessive, environmentaldamage. And the errant spray meant to kill plant predators, when theyswallow or absorb the poison thru their skins, is a threat to the healthof other living beings.

This is a problem when tall-standing plants, such as, grapevines, berrybushes and trees are spayed. Growers are liable, for all injury, topeople or their neighbors plants and animals that occur from such drift.But the injured people, often, do not realize who is responsible fortheir misfortune.

Commercial vineyards in the West are very large, and they are sprayed,usually from the air, using small, lightweight planes. This produces avery high amount of drift.

In the East, the vineyards are smaller, and they are sprayed byapparatus, mounted on a cart, pulled by a utility tractor. The rows,between the grapes, are set at a standard ten foot spacing, in both, theWestern and Eastern part of the country. This allows a tractor to move,easily, between the grape rows.

A utility tractor pulling a spray cart will, at the same time, spray theleft side of the left-hand row and the right side of the right-hand row.The cart, typically, will carry a piston diaphragm pump driven by arotating shaft coupled to the tractor's PTO, "Power-Take-Off." Theinsecticide flows by gravity from a storage tank, thru an inertia trapand filter, to the pump inlet. At the pump outlet, an adjustable,spring-loaded relief valve is used to split the pump flow. The positive,displacement pump always delivers a constant GPM of insecticide; therelief valve, merely, takes the excess flow not required, at the spraynozzles, and vents it back to the storage tank. A gage, at the pumpoutlet, indicates the static pressure level that is pushing theinsecticide solution to the control valves.

When the tractor operator is driving to the vineyard or making U-turns,at the end of each row of grapes, he must have shut-off control to allthe spray nozzles. And when the first or last row is being sprayed, hehas to be able to shut-off flow to the left side or right side nozzles.Ordinarily, this is done with manual valves, located near the operator'sseat. Two high pressure hoses run from a tee fitting, located after thepressure gage, to these valves; then the hoses go back from the valvesto the two spray manifolds on the cart.

Insecticide left standing, for some time, in water loses its strength.Fresh spray mixtures are prepared before each application. Wettable,pesticide powder tends to settle to the bottom of a storage tank,therefore, a mechanical agitator is needed to keep it in suspension. Thepower required to drive the agitator is taken, thru a V-belt and sheavecombination, from the utility tractor's PTO.

When the spray nozzles are located on the cart, most of the sprayparticles, coming out of the nozzles, are too small to have enoughthrust to reach the grapevines. And a very environmentally, damagingresort is employed. A large, shrouded, propeller fan is used, at theback of the cart, to pull the air, from behind the cart, and direct itforward towards the tractor. The air strikes a circular plate, placed afew inches in front of the fan, and flairs out, with great velocity,towards the vines. For the two manifolds their spray nozzles are locatedon the left and right circumference of the plate, respectively. overabout a ninety degree quadrant. This strong, artificial wind carries thetoxic particles to the grapevines. The top of the round plate has anoverhang to keep the air from coming straight up. And the power, todrive the fan, is tapped from the tractor's PTO by a collection ofpulleys, V-belts and shafts.

A vineyard being sprayed with insecticide solution, at the rate of IOGPM with the assist of a 25,000 CFM fan, will have about 25% of thechemical blown around as dry, recrystallized powder. In other words, theforced, fan air has evaporated away 25% of the water holding thechemical in solution before it reaches the vines.

The scent of toxic drift permeates the air, after a tractor operator hassprayed but a few yards of grapevines. The chalky, white powder is notonly on the plants, but everywhere else besides. At this time, onlywaterproof clothing and a respirator mask will, adequately, protect theoperator when commercial-strength insecticides, fungicides andbactericides are sprayed. And EPA regulations and State license requiredthem. But on hot, muggy days, the tractor operator will not wear them;they're intolerable. And the estate manager will pretend not to notice,so that the work will get done.

OBJECTS AND ADVANTAGES

My invention has the following,

(a) It does a minimum amount of damage to the environment. Most of theresidue, after spraying, is left on the intended plants; not in the air.

(b) It uses less pesticide. Unlike prior art, it loses less chemical todrift.

(c) It does not require the sprayer to wear protective clothing, and thework becomes more tolerable.

(d) It reduces a grower's legal liability by leaving the sprayedpremises and the surroundings in a safe condition.

DRAWING FIGURES

FIG. 1 depicts the invention being used to spray a vineyard.

FIG. 2 shows the details of the drift confining portion of theinvention.

FIG. 3 shows the details of the drift removing portion of the inventionand the maintenance equipment.

DRAWING REFERENCE NUMERALS:

10 hood

12 curtain at top of hood

14 fingers on hood's side

16 curtain at bottom of hood

18 gasket

20 screen

22 demister can

24 bump on demister can for drainage

26 solenoid valve

28 spray manifold

30 housing for electrical switch

32 spray nozzles

34 guide rod

36 guide ball

38 duct

40 blower

42 header duct

44 filter

46 activated charcoal container

48 drawer for insect box

50 static pressure taps

52 storage tank

54 agitator shaft

56 flexible cable in cover

58 cart

60 shaft to tractor's PTO

62 hitch

64 shadow of tractor's back wheels

66 shadow of tractor's front wheels

68 grapevine post

70 grapevine wire

72 tray for activated charcoal

74 insect box

76 door

78 test manometer

80 foam rubber gasket

82 structure

84 inlet for hood

86 Vee bulge on hood

88 hole in hood

90 wire mesh

DESCRIPTION OF THE INVENTION

My invention is depicted in FIG. 1 spraying a typical vineyard. To showthe apparatus more clearly, however, the grapevines, utility tractor,and spray pump is not shown. But the insecticide storage tank 32 isshown to give a better indication of size.

The invention uses a moving hood 10 suspended over the grapes and posts68, to confine the drift, as both sides of one plant row are sprayed,while enclosed by hood 10. This is equivalent, to the present practice,of spraying the left side of the left-hand row and the right side of theright-hand row. The hood IO is cantilevered, by structural support 82,from one side of spray cart 58. The position of a utility tractorpulling the cart 58 is shown by shadows of its front wheels 66 and backwheels 64. The tractor is attached to cart 58 by a hitch 62.

A bell-mouth inlet 84, on the U-shaped hook IO, is used to gentlycompress the lateral off-shoots of the vines, to the inside, withoutdamaging them when the hood 10 is pulled along the plant row. A Veeshaped bulge 86, on both sides of hood 10, contains a series of spraynozzles 32 at the point of the Vees 86. These bulges 86 provide thedistance, away from the grape leaves, required to, thoroughly, spray theplant. The nozzles 32 and the centerline of the Vees 86 are inclined,slightly, to the rear of hood 10 to keep spray mist from coming out ofinlet 84.

A solenoid valve 26, normally-closed, is placed on top of hood 10 tocontrol the flow into the side manifolds 28. A housing 30, holding anelectrical switch, is mounted on top of inlet 84. A flexible wire,hanging down from the switch lever, closes the switch when the inlet 84passes over posts 68 or the vines. This allows current to flow thru thevalve's solenoid and open valve 26. This automatic feature allows thetractor operator to concentrate on keeping hood 10 centered over the topwire 70, nailed to posts 68. To farther aid him, a guide ball 36attached to rod 34 is cantilevered from the top of inlet 84.

A blower 40 on cart 58, constantly, pulls the drift from hood 10. Thetoxic air is pulled, thru demister 22 and duct 38, by the negativestatic pressure generated at the inlet of blower 40 when its 40 impellerrotates. The positive static pressure, at the outlet of blower 40,forces the drift thru header duct 42, a pleated paper filter 44, andactivated, charcoal container 46. Here the toxic vapor is removed fromthe air. The clean air then passes, thru an opening in the floor of cart58, back into the vineyard.

A rotating shaft 60, attached to a utility tractor's standard, 540 RPM,PTO, drives the impeller of blower 40 thru a collection of V-belts,pulleys and auxiliary axles. Shaft 60, thru the same type of mechanisms,also powers the insecticide pump and agitator.

Storage tank 52 is made rectangular in shape to conserve space, and tolower the center of gravity for the cart 58. Prior art spray cartsgenerally, have cylinderical tanks.

FIG. 2 shows the drift confining portion of the invention in detail. Allof it is located on the suction side of blower 40.

A short, supple curtain 12 is hung from the top of hook 10, at its rear,and curtain 16 is hung from the bottom edges of both sides, after theVee bulges 86. In addition, short, flexible fingers 14 are attachedtowards the inside of hood 10. The slotted curtains 12, 16 and fingers14 block off unwanted air openings to the hook 10 and force more of theair to enter thru the inlet 84. This results in a more thorough sweep ofdrift out of hook 10.

The polluted air exits the hood 10 thru hole 88, screen 18, and demister22. The demister can 22, filled with wire mesh 90 is located afterscreen 20. Screen 20, on hole 88, prevents the grape leaves and vinesfrom tearing off as hood 10 moves. Mesh 90 removes from the air,entering duct 38, any liquid droplets it may contain. The droplets wetmesh 90 and the coalesced liquid flows down to the bottom of can 22. Asloped, flat spot 24, bumped into the bottom of can 22, drains anyliquid collected back into hood 10. Gaskets 18 seal the connection ofdemister can 22 and screen 20 to hole 88.

FIG. 3 shows the drift removal portion of the invention and themaintenance equipment required to insure the apparatus is workingproperly. All of it is located on the positive pressure side of blower40.

Exploded view, FIG. 3, shows header duct 42, paper filter 44 andcharcoal container 46. The paper filter 44 is used to remove the dustand dry, chemical powder from the air. Static pressure taps 50, whichare normally capped off, are used to check the operating condition offilter 44. A clear, plastic tube manometer 78, filled with a few inchesof water, is attached to taps 50. When the blower 40 is running, if theindicated pressure drop across the filter 44 exceeds the manufacturer'sallowable amount, filter 44 has to be replaced.

A door 76 allows trays 72, holding activated charcoal, to slide intocontainer 46. A foam rubber gasket 80, on door 76, firmly seats thetrays into place when door 76 is closed. Trays 72 have a removablescreen on top and a fixed screen on the bottom. This permits theequipment owner to, economically, replace spent charcoal from a supplydrum. The drawer 48, on the bottom of container 46, is used to hold abox of insects. These insects are trapped, on the premises of the areato be sprayed, and placed in screen box 74. After spraying, if theinsects are alive the air in the vineyard is safe. But if they are dead,the activated charcoal has to be replaced. With experience, the user'slogbook will indicate how often the charcoal has to be replaced for thevarious toxic chemicals used.

In summary, my invention reduces the amount of toxic drift made by priorart spraying. It does this thru spraying close to the plants. Only theair pulled into the hood gets saturated with insecticide. In addition,the air from the hood is cleaned of poison before it is allowed backinto the premises.

Although the preceeding discussion, specifically, calls for activatedcharcoal, as the toxic removing compound, this does not preclude the useof other gas absorbing compounds in container 46.

The apparatus was shown in a vineyard spraying operation. But it can beused to spray berry bushes, nursery trees and other tall standingplants.

If the distance, between plant rows, is accurately maintained, anadditional hood, on the opposite side of the cart, can be used. Thiswould cut in half the time needed to spray. And it would counterbalancethe hood on the other side of the cart. The single hood requires acounterbalance weight on the cart.

In an alternative embodiment of the hood, it may be made withlightweight tubing and waterproof cloth loosely stretched over thetubular frames. And the sides of the hood can be made adjustable.

I have explained the principle of my invention, and illustrated what Inow consider its best embodiment. But it must be understood that, withinthe scope of the appended claim, the invention may be practicedotherwise than as, specifically, illustrated and described.

I claim:
 1. A method of confining and removing drift from agriculturalsprays, comprising of the following steps:(a) attaching a hood to spraynozzles so that said hood covers said nozzles and confines the spraydrift without impeding the movement of said nozzles along a line ofplants and (b) evacuating said drift from said hood by means of thenegative, static pressure created, at the inlet, of a rotating blowerimpeller and (c) removing the toxic chemicals from said drift, togovernmental approved safe limits, by forcing said drift thru gasremoving compounds by means of the positive, static pressure created, bysaid rotating blower impeller, at the outlet of said impeller.